Electric compressors having a configuration in which an electric motor is integrated in a housing are used as compressors for air conditioning apparatuses installed in electric cars or hybrid cars. The electric compressors generally incorporate an inverter, on the periphery of the housing, that converts DC power supplied from a high-voltage power supply to three-phase AC power and that supplies the power to the electric motor via a glass-sealed terminal, so that the rotational speed of the compressor-driving electric motor can be variably controlled.
In the related art, for example, in electric cars and hybrid cars, operation of an electric compressor for an air conditioning apparatus to cool a battery during charging of the battery is known. To operate the electric compressor, a controller area network (CAN) communication line is used in which a control and communication circuit provided on the CPU board of the inverter and vehicle-side control units provided at the vehicle side are connected via a communication cable.